If you look back at the version history, see if you can locate a version where the problem appears for the first time. Who made the edits at that time? Does the problem ever appear for the first time after your version updates or is it only when other individuals edit the file.

Then maybe take a look at that person's machine and perhaps get them to demonstrate how they open and edit files either on the network or when connected via VPN. If you can find some reproducible actions on that machine then you will have a chance of finding the cause of the problems.

__________________
Andrew Lockton
Chrysalis Design, Melbourne Australia